Method of filling containers under aseptic conditions



Sept. 12, 1967 cHmG'c. LOO 3,349,671

METHOD OF FILLING CONTAINERS UNDER ASEPTIC CONDITIONS Filed Aug. 10,1964 2 Sheets-Sheet 1 @H/NG (2. Eco

INVENTOR PRODUC-T STEJZSLE Al 2 ATTORN 5y p 1967 CHINGC. LOO 3,340,671

METHOD OF FILLING CONTAINERS UNDER ASEPTIC CONDITIONS Filed Aug. 10,1964 2 Sheets-Sheet 2 INVENTOR. @H/NG (l. Loo

BWKZW ATTORNEY United States Patent Ofifice 3,340,671 Patented Sept. 12,1967 3,340,671 I METHOD OF FILLING CONTAINERS UNDER ASEPTIC CONDITIONSChing C. Loo, Los Angeles, Calif., assignor to Carnation Company, LosAugeles, Calif., a corporation of Delaware Filed Aug. 10, 1964, Ser. No.388,400 Claims. (CI. 53-37) This invention relates to a method andapparatus for introducing a fluid or flowable material into a flexiblecontainer. More particularly, the invention concerns a method foraseptically filling a flexible container with a liquid or liquids havingentrained solids, and a method for protecting a sealing surface duringfilling flexible containers.

Many liquids, including foods, are packaged for sale in flexiblecontainers such as laminated plastic, aluminum foil and cellophane. Theintroduction of foods to flexible containers has presented a number ofproblems. Major among these is sealing the container after introducingthe food. A common practice is to fill the flexible container throughthe top while maintaining the container under aseptic conditions, andthen seal the container along the top edge. Most liquid productintroduced to containers under pressure splashes over the inside wall ofthe container. Steam or liquid sterilizing agents, such as chlorine,used to sterilize the opening in the container often oxidizes a part ofthe inner surface of the container. If the liquid product splashes onthe area of the container Where theseal is to be made, or if this areais oxidized, it is extremely difficult to obtain a positive seal of thecontainer along this surface. A major portion of food product spoilage"or leakage of liquids in flexible packaging is attributed to suchimperfect seals.

It is an object of this invention to provide a new method and apparatusfor introducing fluids to flexible containers. A further object of thisinvention is a method of introducing liquids to flexible containersunder aseptic conditions. A further object is a filling method whichinsures a dry, clean inner surface will be available for sealing thecontainer.

9 Yet, another object of the invention is a unique method and apparatusfor filling steralized containers under aseptic conditions. Furtherobjects will be apparent to those skilled in the art upon reading thefollowing detailed description of the'invention.

FIGURE 1 is a side view of a flexible container which has beenfilledwith a liquid and sealed by the method of this invention.

i FIGURE 2 shows a side view of a flexible container prior to filling,and it particularly illustrates the pocket utilized by this invention.

FIGURE 3 is an oblique view along line 33 looking directly into, thepocket formed in the corner of the container shown in FIGURE. 2. 7FIGURE 4 is a perspective view of the preferred apparatus forintroducing liquid to the flexible container. The figure alsoillustrates the position of the flexible container just prior toengaging the filling apparatus.

; FIGURES is a section view of the cone of the filling apparatus and aportion of the flexible container after the cone is positioned in thepocket of the container.

FIGURE 6 is a section through the filling apparatus and a part oftheflexible container; it further illustrates the relationship of thecontainer to the filling apparatus just prior to puncturing thecontainer.

FIGURE 7 is a section through the filling apparatus along line 77 ofFIGURE 6, and it illustrates the general construction of the cone. v

FIGURE 8 is a section through a portion of the filling apparatus andflexible container as shown in FIGURE 6, except the view is subsequentto puncturing the container.

FIGURE 9 is also a side section showing the withdrawal of the fillingtube from the container and the simultaneous unfolding of the pocket.

FIGURE 10 illustrates the seal across the corner of the flexiblecontainer after withdrawal of the filling tube.

The invention embodies concepts of: 1) Filling a flexible container soas to provide a protected inner sealing surface. This involves forming adepending pocket in the container so that the inner surface of thepocket and inner surface of the container form a protected surfaceduring filling; filling the container through an opening in the pocket;unfolding the pocket to bring together the protected inner surfaces; andsealing the container along the protected inner surface, and (2) Fillinga sterile flexible container under aseptic conditions by sterilizing adepending pocket in the flexible container, and purging the pocketduring filling to maintain the pocket sterile; puncturing the pocket,and filling the container through the opening in the pocket; unfoldingthe pocket and sealing the opening in the container.

The invention will be described with reference to the preferredembodiment using aseptic filling conditions and a liquid food product.In the preferred embodiment, the flexible container 11 is apresterilized sealed container made of impermeable material, such aslaminated plastic, cellophane, laminated metal foil, etc. It is notessential to use a presterilized container if the product is to besubsequently sterilized, or if sterility is not important. The inventionis applicable to non-food products (where sterility is not important)and will provide a clean, dry sealing surface for any flexible packagingfilled with a flowable solid or liquid. In particular, the invention isuseful to form a clean, dry sealing surface in flexible containers fornon-sterilized products which are filled with liquid containingentrained fibrous material, solid chunks, grease, chemicals orcorrosives which' would bridge a heat seal.

In a commercial operation the pocket 12 may be formed pneumatically, ormechanically by simply pressing a blunt wedge into a corner of asuspended containerv 11. To facilitate forming the pocket 12 in thesealed container 11, it is desirable to slightly preheat the container11 to release the partial vacuum inside the sealed container 11. It ispreferred that the pocket be formed in a corner of the container sincethis facilitates easy sterilization, puncturing and sealing of thecontainer 11. The container may have any number of corners. For example,a pentagon has been found to be an advantageous shape since it providesa balanced center corner in which to form the pocket.

FIGURE 3 is a view looking directly in the pocket 12, and it illustratesthat the preferred pocket 12 is a depending fold or crease in the cornerof container 11.

During the filling operation the container 11 may be suspended bymechanical means, such as the clamps 24 and 26 shown in FIGURE 5. Thepocket 12 may be held open pneumatically or mechanically if desired. Theapparatus suspending the container 11 during filling has been eliminatedfrom all figures except 5 and 6 to more clearly illustrate the relationbetween the filling apparatus 13 and container 11.

If a rectangular container, as shown herein is used, a

- 60, so that the cone 14 and pocket 12 fit snugly. While it is notnecessary to form a seal between the cone 14 and pocket 12 during thefilling operation, the snug fit between the cone 14 and pocket 12facilitates maintaining sterility during the filling operation. It isalso possible to use an elliptical cone and pocket, so the particularangle of either the cone 14 or pocket 12 is not important, so long asthey fit snugly together at some point inside the pocket.

FIGURE 5 shows the cone 14 of the filling apparatus 13 after it has beeninserted into the pocket 12. As explained, the container 11 may be heldin position against the cone 14 by the clamps 24 and 26. FIGURE 5particularly illustrates a distinctive feature of the invention. Thepocket 12 and the container 11 form a double wall around the perimeterof the cone 14. The inner surface of the pocket 12 is adjacent to theinner surface of the container 11. The inner surface of the pocket 12along the elevation of the cone 14 is protected from splashing prodnotand oxidation in the loop formed by the container 11 and pocket 12. Theclamps 24 and 26 as shown serve a duel purpose: they help hold thecontainer 11 in position against the cone 14 during filling; and theypress the wall of the container 11 against the wall of the pocket 12 soas to further protect the inner wall of the pocket 12 during the fillingoperation. Thus, the inner surface of the pocket 12, and protected areaof the container 11, which will be the sealing area when the pocket 12is unfolded, are protected. The conical clamps 24 and 26 are notessential to the invention, since the inner surface of the pocket 12will be protected by the wall of the container 11 if the container issupported during filling.

In FIGURE 6 the cone 14 of the filling apparatus 13 is shown in thepocket 12. The pocket 12 is maintained sterile by introducing a purgegas such as steam or sterile gas through tube 16 and annulus 17. Thepocket 12 may be presterilized by means such as chlorine washing. Smallamounts of residual chlorine left in the pocket are useful in keepingthe outside surface of cone 14 free from contaminants. During thefilling operation and prior to puncturing, pocket 12 is purged. The flowof purge gas through tube 16 and annulus 17 may continue for the entirefilling operation to maintain the container 11 sterile.

The filling apparatus 13 comprises afilling tube 18, flexible rubbertube 21, cone 14, an upper housing and lower housing 19. In theillustrated embodiment, the lower housing 19 and cone 14 remainstationary during filling. The lower housing 19 may be supported bymeans attached to flange 15. The housing 10, cone 14 and rubber tube 21form a seal so that air may enter only through the nose of cone 14 orthrough tube 16. As illustrated, the filling tube 18 moves with theupper housing 10 and slideable within the lower housing 19. Supports 20and guide the sliding tube 18.

Purge gas is introduced to the annulus 17 through the tube 16. Allapparatus inside the flexible rubber tube 21 are sterilized by meanssuch as steam, chlorine solution, etc., and can be maintained sterile bycontinuing to purge the annulus 17 with sterile gas. Product enters thefilling apparatus 13 through the annulus 17 in the filling tube 18.Suitable means for controlling the flow of product and metering theproduct may be provided at the input to the filling tube 18.

FIGURE 8 shows the filling tube 18 after puncturing the pocket 12. Inthe illustrated embodiment, the filling tube 18 slides downwardly bydepressing upper housing 10 and slidable tube 18 as shown in FIGURE 6.The slidable tube 18 aflixed to the housing 10 as a means of insertingthe tube 18 into the container has the additional advantage of causingthe rubber tube 21 and annulus 17 to act as a bellows when the housing10 and filling tube 18 are depressed. The surge of gas through the noseof the cone 14 at the instant the tube 18 punctures the pocket 12 causesthe container 11 to partially inflate so that the filling tube 18 orbarb 22 does not tear the walls of the container.

It is desirable to have a slight positive pressure within the annulus 17when filling the pocket 12. The positive pressure prevents contaminatedair from entering between the pocket 12 and cone 14, and aids inexpanding the container 11 so that the filling tube 18 or barb 22 doesnot accidently rip the sides of the container 11 when inserted orWithdrawn.

After puncturing the pocket 12 sterile product such as milk, tomatoes orany other liquid susceptible of spoilage, is fed into the container 11through annulus 30 in the filling tube 18. As mentioned, the purge ofannulus 17 with steam or sterile gas may continue during the fillingoperation in order to prevent contamination entering between the cone 14and pocket 12.

When a prescribed amount of product has entered container 11, the flowof product is discontinued and the filling tube 18 is retracted. Thefilling tube 18 is provided with barb 22. The function of the barb 22 isto simultaneously unfold the pocket 12 as the filling tube 18 iswithdrawn from the container 11. FIGURE 9 particularly illustrates thewithdrawal of the filling tube 18 from the container 11. As the fillingtube 18 retracts, the barb 22 snags the pocket 12. The pocket 12 isdrawn into the nose of the cone 14. The continuous flow of purge gasdown the annulus 17 and out the nose of the cone 14 maintains thecontainer 11 sterile while the pocket 12 is unfolded.

The container 11 is lowered, or alternatively the cone 14 and fillingtube 18 are raised so as to completely unfold the pocket 12, and thecontainer 11 is sealed at 23 by a method such as heat sealing or othertechniques known in the art. When using the pocket 12 to asepticallyfill a sterile container 11, it is preferred to seal the container alongthe protected inner surface formed by the pocket 12. However, it is notessential to do so. The sequence of removing the filling tube, unfoldingthe pocket and sealing the container is illustrated by FIGURES 8, 9 and10.

When the invention is to be used to fill a container with a liquid whichneed not be aspectic and a clean sealing surface is desired, thepreferred procedure is like that described for aspetic filling, exceptthe pocket need not be sterilized and no purge is necessary. The pocketis formed, preferably in the corner of the container, and a fillingapparatus similar to that illustrated in FIGURE 6 may be used topuncture the pocket 12, fill the container, and unfold the pocket tobring into sealing relationship the protected inner surfaces of thepocket and container. The container is sealed along the protectedsurface by a method such as heat sealing.

Naturally, the invention can be used for aseptically filling a flexiblecontainer with some solids, pastes, flowable solids and powder, and forproviding a protected sealing surface when packaging any of thesematerials.

While the invention has been described with reference to a particularpreferred embodiment, it will be appreciated that modifications of thepreferred embodiment will occur to those skilled in the art upon readingthe foregoing specifications. Accordingly, it is intended that thosemodifications which fall within the broad scope of the appended claimsbe included.

Having described the invention, what is claimed is:

1. A method of filling a flexible container under aseptic conditionswhich comprises:

(A) Forming a depending pocket in the container;

(B) Sterilizing the pocket and continuously purging the pocket with asterile purge gas;

(C) Puncturing the pocket with a filling means, and filling thecontainer through the opening in the pocket;

(D) Unfolding the pocket while continuing to purge the area surroundingthe opening in the pocket;

(E) Sealing the container.

2. A method of filling a sterile, sealed, flexible container underaseptic conditions which comprises:

(A) Forming a depending pocket in a corner of the container;

(B) Sterilizing the pocket and continuously purging the pocket with asterile purge gas;

(C) Inserting a filling means into the pocket to puncture the pocket andfill the container;

(D) Withdrawing the filling means and simultaneously unfolding thepocket;

(E) Sealing the opening in the container.

3. The method of claim 1 wherein the containers is sealed along theprotected inner surface exposed by unfolding the pocket.

4. The method of claim 2 wherein the container is sealed along theprotected inner surface exposed by unfolding the pocket.

5. A method of filling a sterile, sealed, flexible container underaseptic conditions which comprises:

(A) Forming a depending pocket in a corner of the container so as toform a protected inner surface between the walls of the pocket and thecontainer;

(B) Inserting a filling means into the pocket and continuously purgingthe pocket;

(C) Puncturing the sterile pocket and filling the container through theopening in the pocket;

(D) Withdrawing the filling means and simultaneously unfolding thepocket to bring into sealing relation the protected inner surfaces ofthe container, while continuing the purge from the filling means in thearea of the opening so as to prevent contamination from entering theopening;

(E) Sealing the container along the protected inner surfaces. ReferencesCited UNITED STATES PATENTS 2,708,067 5/1955 Paton 229-62.5 2,861,40611/1958 Holsman et a1. 53385 X 3,040,967 6/ 1962 Klein 229-625 TRAVIS S.MCGEHEE, Primary Examiner.

1. A METHOD OF FILLING A FLEXIBLE CONTAINER UNDER ASEPTIC CONDITIONSWHICH COMPRISES: (A) FORMING A DEPENDING POCKET IN THE CONTAINER, (B)STERILIZING THE POCKET AND CONTINUOUSLY PURGING THE POCKET WITH ASTERILE PURGE GAS; (C) PUNCTURING THE POCKET WITH A FILLING MEANS, ANDFILLING THE CONTAINER THROUGH THE OPENING IN THE POCKET;